1. Field of the Invention
The present invention relates to a semiconductor device which limits use of a memory cell unit, a processor unit or the like by a password. In addition, it relates to a BIOS authentication system which limits authentication of a basic input-output system (BIOS) by a password.
2. Description of the Related Art
Today, services through the internet are combined with mobile technology to be used anywhere and anytime, and thus a theft incident of a business mobile (notebook PC or the like) is recognized as a serious threat to network security. For example, access to an in-company network through the stolen mobile is far more serious than that to information recorded in an HDD.
To solve such a problem, there is available a BIOS password technology which applies a password on a BIOS during booting. However, it relies on individual management by a mobile user, and a danger may be increased depending on user's understanding of security. The password of the stolen mobile can be decoded with sufficient time to release locking. This is because the password or its information exists in the HDD.
Against such a background, Intel Corporation has proposed direct mounting of preboot type security in a BIOS in a PC security technology system called a trusted platform module (TPM: http://developer.intel.com/design/mobile/platform/downloads/Trusted Platform Module White Paper.pdf). This trend is similarly observed in US Phoenix Corporation's “cME FistBIOS” which causes a BIOS to recognize a PC on a network (see: http://www.phoenix.com/en/Products/Core+System+Software/Phoenic+cME+FirstBIOS/default.htm).
Conventionally, therefore, there is an urgent social need to establish firm security between a mobile device such as a notebook PC and an infrastructure such as a network, and expectation is now placed on a security technology which incorporates authentication codes in the BIOS. Permission of use by authentication may be applicable not only to BIOS authentication but also to limited use of a processor unit such as a CPU.
Thus, there has been a demand for a semiconductor device which can limit use of a memory cell unit or a processor unit by a password, thereby improving security, or a BIOS authentication system which can limit authentication of BIOS use by a password, thereby improving security.